The present invention relates to a wire terminal connector, and more particularly, to a crimped terminal wire having a rubber plug.
Conventionally, a thin insulated wire 30 having a rubber plug shown in FIG. 4 is inserted into a connector that is used in a place where water-proof capability is required. That is, a rubber plug 32 for sealing is engaged with a boundary portion of a core wire 31 of the thin insulated wire 30, so that a connecting portion between the insulated wire 30 and the wire insertion hole of a connector housing can be tightly sealed.
In this connection, the rubber plug 32 is made of silicon rubber and formed into a cylindrical shape. After the rubber plug 32 has been inserted with the wire 30, it is prevented by the clamping or crimping action of a terminal fitting 33 from being disconnected. As shown in FIG. 4, the conventional terminal fitting 33 includes a wire barrel 34 that clamps or crimps the core wire 31 and an insulation barrel 35 that clamps the rubber plug 32. Both ends of the insulation barrel 35 are separated and curved along an outer circumferential surface of the rubber plug 32 in the process of clamping. At this time, an appropriate crimping force is given to the insulation barrel 35, so that the rubber plug 32 is prevented from being disconnected.
In the above crimping system, the insulation barrel 35 is crimped under the condition that both ends are butted against each other. Therefore, when a crimping force is applied to the insulation barrel, both ends bite onto a surface of the rubber plug 32. For this reason, the clamping portion of the rubber plug 32 may be cracked, which could cause the wire to be damaged or disconnected, Also, the same metal terminal fitting 33 is applied to a plurality of types of wires (rubber plugs) as long as the outer diameter is in a predetermined range. Therefore, it is difficult to provide a constant clamping force. In other words, when the outer diameter of the plug is small, the insulation barrel is too big and the ends of the insulation barrel cannot apply an adequate crimping force to the plug (see FIG. 3). The critical bending radius of the clamp pieces 9a and 9b is larger than the diameter of the rubber plug, which causes the guide piece 9b (FIG. 3) to lose contact with the surface of the plug 3a. When the outer diameter of the plug is large, the insulation barrel is too small and the ends of the insulation barrel cut into the outer diameter of the plug (FIG. 5). When a sufficient crimping farce cannot be provided to the rubber plug 32 because of a mismatch between the sizes of the plug and the insulation barrel, a positional slippage is caused in the rubber plug 32 in the case where the thin insulated wire 30 is inserted into an insertion hole of the wire. When the insulation barrel 35 is clamped again, the working efficiency is remarkably decreased. The above problems are encountered in the crimping system of the prior art.
In addition, the insulation barrel is crimped onto a member made of rubber, the resilience of which is high. Essentially, it is difficult to crimp the insulation barrel to the rubber plug because of the springiness of the resilient material. As a result, an unnecessarily high crimping force tends to be applied in an effort to make up for the insufficient crimping effect.